SFP+ module not holding in port

There are two types of optical transceiver problems – software-based and hardware-based. This time definitely we talk about a hardware-based problem. The SFP module is not locking in the port. This means when the engineer plugs it into the switch port, the SFP module is not producing fixating noise (click), and does not fixate itself in the port. As a result, the module can be easily pulled out. This is dangerous because it allows someone to mistakenly trip on the cable or pull on the optical fibre, and the SFP module pops out. Practically, this problem is observed mostly with a few 10G-SFP modules plugging into CISCO ASR, Huawei, or EXTREME switches, but in general can happen to any vendor equipment.

After diagnosing the SFP module hardware and comparing it with the module that locks in the port successfully, we can see that some hardware differences obviously cause this problem. The locking mechanism consists of a fixating peg, sliding plate, and handle. In the normal process, when an SFP module is slid into a switch port, the port has a locking leg that fixes the SFP module with the peg. Pulling the handle on the sliding plate on the SFP module moves it, and with two-handed 45-degree pins, slides under the switch’s locking leg, raises it, and releases the SFP module from the port. Problematic SFPs have a thicker sliding plate end that supports the handle. As a result 45 45-degree pins on the other side of the SFP sliding plate are too close to the locking peg, and when the SFP is inserted into the switch port, the switch’s locking leg can’t fit between the 45-degree pins and the SFP locking peg. The module is not fixed in the port.

SFP casings